To ensure long life and reliability you must properly break in your freshly assembled engine.

For a high performance street motor fill the engine with a good grade 20W-50 Mineral based oil. Fill the oil filter with oil before installing it. Remove the spark plugs and crank the engine until the oil pressure comes up on the gauge.

Re-install the spark plugs. Now you are ready to start her up. Start the engine and bring it immediately to 2,000 rpm. Vary the engine speed between 2,000 – 3,000 rpm for about 30 minutes. After 30 minutes stop the engine, check the valve lash and re-torque the head bolts. Drain the oil and change the filter. Re-fill the engine with 20W-50 Mineral based oil.

Drive the car slowly for about 500 miles keeping the rpm under 4,000. Don’t lug the engine either because that’s worse for the motor than over revving it. After 500 miles change the oil and filter again. You can now use a synthetic oil if you want to. Use a 20W-50 oil and change it every 3,000 miles. Your engine is now broken in.

For a race engine broken in on the dyno the procedure is a little different. Note that this procedure is for a race clearanced engine.

For the initial run use a Mineral based 20W-50 oil. Run a hotter spark plug than you normally would run. Prime the oil system and the fuel system. Start t6he engine and bring it up to 2,000 – 3,000 rpm with no load. Watch the oil pressure and check for leaks. After 30 minutes stop the motor, check the timing, re-torque the head and check valve lash. Then, run the engine with a light load between 2,000 – 3,000 rpm for another 30 minutes. After 30 minutes change the spark plugs to the normal heat range you are going to run. Do a full throttle full load pull up to the bottom of the power band. Quickly chop the motor.

Check the spark plugs and the BSFC numbers if your dyno is equipped to do so to confirm the jetting. If everything looks good do a full throttle full load pull.

The engine is now ready to race.

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